HOW THE CHIP WORKS

--The microprocessor acts as the brain of the computer, and it doles out instructions for every component

A computer consists of hundreds of parts, including a monitor, mouse, disk drives and keyboard

Inside the computer is a circuit board. It houses all sorts of microchips, including those for ROM (read-only memory) and RAM (random-access memory)

Mounted on the circuit board is a microprocessor, which is housed in a protective container and connected to rows of gold-plated pins

Inside the microprocessor package is the chip itself. This tiny square of silicon is packed with transistors that process instructions and data for the computer

--Scientists have managed to squeeze millions of transistors onto each chip

Each transistor on the surface of a silicon chip acts as a switch that can open or close a gate. Computers process information by manipulating sequences of opened and closed gates. A positive charge applied to the gate attracts electrons, allowing current to flow across the gap from the source to the drain. A negative charge stops the current and closes the gate

--A Pentium II chip can process 500 million instructions every second. Here's how:

Information flows into the chip... The bus interface unit retrieves data and instructions from the computer's main memory (RAM)

Information goes either to a code cache, which stores the instructions that tell the processor what to do...

...or to a data cache, where the data to be processed are stored until needed by other parts of the microprocessor

...where it's processed...

The branch predictor unit anticipates the most likely path the instructions will take, thus getting a head start on the work

The instruction fetch and decode unit translate instructions into simple operations that the execution units can perform

The reservation station and reorder buffer determine the most efficient order for instructions to be processed

The heart of the chip is its execution units. They perform various operations and send results back to the data cache

The floating point unit handles mathematical operations on the largest and smallest numbers

...then sent out into the computer

The data cache ferries the processed information to the bus interface unit, which in turn sends the results to RAM